Helium Gas Detection Technology

Theory of Helium Gas Detection

The theory behind Helium gas detection is rather simple. Since Helium is lighter than air--it has a molecular weight of 4 and air has a molecular weight of 30--if introduced into an empty pipe with a break in it, the Helium gas molecules will exit from the opening, rise through the subsurface, and exit from the ground at the exact point where the break is.

Gas Leak Detector

We use the MGD-2002 Multi-Gas leak detector, which is manufactured by Dielectric, a subsidiary of the SPX Corp. of Raymond, ME. This instrument, which is composed of a detector unit, hose, and ground probe sensor, is the ideal instrument for detecting leaks in pipes, storage tanks, or any closed system that can be pressurized with the tracer gas.

MGD-2002 Multi-Gas leak Detector

Pinpointing a Water Leak Using the Helium Gas Detector

An underground water leak can be found with the Helium gas detector using the following 6-step procedure:

1. Mark the Location & Depth of the Water Line

Because the gas survey must be conducted by passing the ground probe sensor across the entire length of the line in question, its location and depth must first be determined.

2. Turn the Water Service Off

The water service is temporarily turned off from a shut-off valve.

3. Drain the Water Out of the Line

An air compressor is used to blow water out of the line.

4. Open & Isolate the Line

The line is shut off at one end and opened up at the other.

5. Pump Helium Gas into the Line

A Helium-Air mixture is pumped into the open end of the line using an air compressor.

A Compressor & Gas Tank Pumping Helium into a Water Line

6. Conduct a Helium Survey

The ground probe sensor is run across the line to search for the highest concentration of Helium gas.

A Technician Conducting a Helium Survey to Look for  Water Leak

7. Designate the Location of the Leak

The location with the highest concentration of Helium is marked on the ground with pink paint and/or flags, thereby indicating the location of the underground water leak.

Advantages of Helium Gas Detection Technology

  • Can be used in noisy environments.
  • Pipe material does not affect results.
  • Works about 99% of the time.
  • Easy to use, with little ambiguity.

Limitations of Helium Gas Detection Technology

  • Water service must be shut off.
  • The pipe must be cleared and isolated.
  • Helium will not always penetrate reinforced concrete.
  • Helium can be deflected by large rocks and bedrock.
  • Cannot be used on sleeved pipes.